From 1d7970be045927a43bc3d7828c82a758cf4ec322 Mon Sep 17 00:00:00 2001
From: Jukka Rissanen <jukka.rissanen@nordicsemi.no>
Date: Fri, 10 May 2024 20:29:50 +0300
Subject: [PATCH] net: context: Do not check our own ports

There is no need to check our own context when going through
the used ports in the system. This prevents error when binding
in some corner cases.

Fixes #72035

Signed-off-by: Jukka Rissanen <jukka.rissanen@nordicsemi.no>
---
 subsys/net/ip/net_context.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/subsys/net/ip/net_context.c b/subsys/net/ip/net_context.c
index 77d829a570fd6f..20b85237aea27f 100644
--- a/subsys/net/ip/net_context.c
+++ b/subsys/net/ip/net_context.c
@@ -156,7 +156,8 @@ static inline bool is_in_tcp_time_wait_state(struct net_context *context)
 #endif
 }
 
-static int check_used_port(struct net_if *iface,
+static int check_used_port(struct net_context *context,
+			   struct net_if *iface,
 			   enum net_ip_protocol proto,
 			   uint16_t local_port,
 			   const struct sockaddr *local_addr,
@@ -170,6 +171,10 @@ static int check_used_port(struct net_if *iface,
 			continue;
 		}
 
+		if (context != NULL && context == &contexts[i]) {
+			continue;
+		}
+
 		if (!(net_context_get_proto(&contexts[i]) == proto &&
 		      net_sin((struct sockaddr *)&
 			      contexts[i].local)->sin_port == local_port)) {
@@ -313,7 +318,7 @@ static uint16_t find_available_port(struct net_context *context,
 
 	do {
 		local_port = sys_rand16_get() | 0x8000;
-	} while (check_used_port(NULL, net_context_get_proto(context),
+	} while (check_used_port(context, NULL, net_context_get_proto(context),
 				 htons(local_port), addr, false, false) == -EEXIST);
 
 	return htons(local_port);
@@ -327,7 +332,8 @@ bool net_context_port_in_use(enum net_ip_protocol proto,
 			   uint16_t local_port,
 			   const struct sockaddr *local_addr)
 {
-	return check_used_port(NULL, proto, htons(local_port), local_addr, false, false) != 0;
+	return check_used_port(NULL, NULL, proto, htons(local_port),
+			       local_addr, false, false) != 0;
 }
 
 #if defined(CONFIG_NET_CONTEXT_CHECK)
@@ -794,7 +800,7 @@ int net_context_bind(struct net_context *context, const struct sockaddr *addr,
 
 		ret = 0;
 		if (addr6->sin6_port) {
-			ret = check_used_port(iface,
+			ret = check_used_port(context, iface,
 					      context->proto,
 					      addr6->sin6_port,
 					      addr,
@@ -894,7 +900,7 @@ int net_context_bind(struct net_context *context, const struct sockaddr *addr,
 
 		ret = 0;
 		if (addr4->sin_port) {
-			ret = check_used_port(iface,
+			ret = check_used_port(context, iface,
 					      context->proto,
 					      addr4->sin_port,
 					      addr,